Today there is an increasing need to supplement multimedia systems, that present audio and visual data to a user, with additional sensory stimuli. Multimedia systems such as televisions, portable devices, and video games are being enhanced through the introduction of improved screens and network capabilities. In addition to these more traditional areas of improving user experience, another area of consideration is tactile stimulation. In combination with improved audio and visual effects, tactile stimulation can make a game or movie experience much more realistic and memorable.
Currently, there exists devices such as piezo-electric transducers that are capable of specifically providing tactile stimulation. These devices have to be controlled by a driver that is separate from the driver used to control audio or visual output. Thus, not only are they separate from audio speakers, they also require additional components for synchronized operation with the rest of the multimedia system.
There are several other types of devices such as bass shakers and multifunction transducers that provide palpable vibrations while also processing audio signals and generating sound. The bass shaker converts the bass component of an electric audio input into vibrations. Bass shakers are driven by a very low frequency signal that causes the device to resonate and thereby generate these palpable vibrations. However, these bass shakers have poor damping characteristics, resulting in lingering vibrations even after the audio/visual data has ended.
Another device that has gained some popularity in providing both audio and tactile stimulation is a multifunction transducer (MFT). MFTs comprise a speaker cone connected to a voice coil, and a magnetic assembly that provides a magnetic field in which the coil operates. Unlike regular speakers, both the voice coil and the magnetic assembly are resiliently mounted and capable of oscillating. The magnetic assembly and the speaker cone can be driven to oscillate by applying signals to the voice coil. The magnetic assembly owing to its mass and compliance of its mounting will oscillate at a relatively low frequency within the range of frequencies that are easily perceptible to a user. Although, MFT's provide both audio and tactile stimulation, their resonant frequencies are predetermined and difficult to modify without completely disassembling them.
Accordingly, a need exists for systems and methods that improve the user's interaction with the content being presented. It is desirable that the system does not distract from the content being presented. It is also desirable that the system be easy to use, portable, inexpensive, and suitable for long term use.